Self-starter for electric motors.



No. 653,470. Patented July [0, 1900.

H. H. CUTLER. SELF STARTER FOR ELECTRIC MOTORS.

(Application flied June 8, 1899.)

2 Sheets-Sheet I.

(No Model.)

m: mums PETERS co PHoTo-Lnuov. WASNINGTON. o. c

Patented July l0, I900.

2 Sheets-sheaf 2.

INV R TTORNQS.

H. H. CUTLER.

SELF STARTER FOR ELECTRIC MOTORS.

(Application filed June 8, 1899.)

(No Model.)

UNITED STATES PATE T (jrricn.

HENRY'H. CUTLER, OF CHICAGO, ILLINOIS.

SELF-STARTER FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 653,470, dated July 10,1900.

Application filed June 8,1899. Serial No. 719,815- (No model.)

To all whom it may concern.-

Be it known that I, HENRY I-I. CUTLER, a citizen of the United States,residing at Ohicago, in the county of Cook and State of Illi nois, haveinvented a certain new and useful Improvement in Self-Starters forElectric Motors, of which the following is a full, clear, concise, andexact description, reference beinghad to the accompanying drawings,forming a part of this specification.

My invention relates to a self-starter for electric motors, my objectbeing to provide means whereby the armature-resistance of the electricmotor may be automatically removed from circuit during the starting ofthe motor.

In accordance with my invention I provide in circuit with the armatureof the motor the usual starting-resistance and provide a plurality ofeleotromagnets arranged to be successively operated to in turn removeportions of the starting-resistance from circuit, whereby the armatureis permitted to start up gradually and build up in speed until normaloperation results. In practice I divide the armature-resistance intosections and provide an electromagnet for controlling each of theseveral sections, the first electromagnet being arranged to becomeenergized when the counter electromotive force of the armature hasreached a certain value, to thereby cut out one of the sections of theresistance and lower the resistance to which the armaturecurrent issubjected, thuspermitting the speed of the armature to increase. Whenthe counter electromotive force of the armature has reached a secondprearranged value, a second electromagnet is energized to remove anothersection of the resistance, and so on, the electromagnets being thussuccessively energized to successively remove the sections of thearmature-resistance from circuit until the desired speed has beenobtained. The electromagnets are 'in practice connected in circuit, sothat the first electromagnet when energized connects the succeedingelectromagnet in circuit. I preferably provide a short circuit about theelectromag- .-net to normally remove the same from operative position,which short circuit when opened includes the, electromagnet operativelyin circuit. The electromagnets are usually made alike and adjusted tobecome energized when traversed by a current of a definite value, and byarranging each electro= magnet to connect the succeeding eleetro- Tmagnet in series with the same the resistance of the path is increased,thereby cutting down the current, and the succeedin g electromagnetremains in circuit unenergized until the rise of voltage brings thecurrent up to the prearranged value.

I have employed the term electromagnet as broadly comprehendingsolenoids'and electrom'agnets, strictly so called.

I have illustrated my invention in the accompanying drawings, in which'7 Figure 1 is a plan View of a self-starter embodying my invention. Fig.2 is a sectional view thereof. Fig. 3 is a diagrammatic viewillustrating the arrangements of the circuits. 1 1,

in the presentinstance as operated by means J of an arm 1?, connectedwith a float b, whereby the arm is raised when the float descends. AWeighted rocking lever 19 is pivoted at b upon the pivot of the arm I)and the switcharm a. tively to the arm I) is limited by the stops 6 bUpon the pivoted end of the lever 19 lugs b b are provided, adapted toengage and move switch-arm a. When the arm I) is raised, the weightedlever 17 is rocked toward the center of gravity thereof and is shiftedbeyond the vertical support, when the said lever falls to the left andthe lug b engaging the arm a, carries the same into engagement with theterminal (0 thereby closing .the circuit. "When the float ascends, thearm b is moved downward, thereby throwing the weighted lever 17 to theright and carrying the switcharm a into engagement with the terminal ato open the motor-circuit.

The main 1 is connected with the terminal The movement of the lever brelaa and the switch-arm a is connected by conductor 3 with the terminal0, between which and the terminal a the resistance d is connected, Whileto the terminals 0 c the resistance d is connected. The terminal 0 isconnected by conductor 4 with one side of the armature e. The other sideof the armature is connected by conductor 5 with the other main 2. Thefieldcoil 6 is connected in shunt with the armature. From the terminal ca conductor 6 extends through electromagnet f, thence by conductor 7 toterminal 9, which is connected with terminal 9 by contact-plate g fromthe terminal g. Conductor 8 extends to conductor 5. A terminal 9 isconnected with terminal g and normally through plate 9 with terminal gterminal 9 being connected by conductor 9 with one end of magnet f,while the other end of said magnet is connected with the end of magnetf. A conductor 10 extends from conductor 9 through winding f thencethrough winding f and conductor 11 to conductor 8. Upon the core f ofthe solenoid or magnet f is carried a contact-plate f adapted when thesolenoid is raised to bridge together terminals c and 0 Upon the core fof magnetf contact-plate) is provided, adapted when the core is raisedto connect together the terminals c and c.

In starting the switch-arm a is moved to terminal a and current frommain 1 passes through the switch, conductor 3, resistancecoils d and d,conductor 1 through the armature'and to the opposite main 2. Circuit isthus closed through the armature and all of the armature-resistance. Theshunt-path for the current around the armature is provided throughconductor 6, magnetf, conductor 7,

contacts gg g, and conductor 8, and when the counter electromotive forceof the armature has been built up to a prearranged value, according tothe turns of the windings of the magnet f, said magnet is energized,drawing up core f and moving plate f against terminals c c toshort-circuit resistance d, thereby cutting out a portion of thearmature-re sistance and permitting the speed of the motor to furtherincrease. The ascent of the core f moves plate 9 out of engagement withthe terminals g g, and the shunt-path around the armature may now betraced over conductor 6, magnet f, magnet f, conductor 9, contacts g 9and conductor 8. When the counter electromotive force of the armature israised to a second prearranged value, magnet f is energized sufficientlyto raise core f thereby moving plate f into contact with the terminals 0c to short-circuit resistance d and move plate 9 out of contact withterminals g 9 The magnets ff are now in shunt with the armature, and asless current than that required to lift the cores in the first instanceis sumcient to maintain the cores in their upper position windings f fare adapted to be connected in circuit with the windings f f in thisposition to serve as resistances to cut down the current through themagnets,and,further more, being in the form of windings they assist inholding the cores in their upper positions. The shunt-circuit may now betraced through conductor 6, windings ff, conductor 10, windings f fconduct-or 11, and conductor 8.

In Figs. 4, 5, and 6 I have illustrated a construction wherein threesections of resistance are provided in the armature. From the main 1 aconductor 12 extends to terminal h, and a conductor 13 extends fromconductor 12 through the winding 70, thence by conductor 14 through theresistances 70 thence by conductor 15 through the contacts 70 70 of thecontroller-switch to the opposite main 2. The end of coil 62 isconnected with terminals c c c and 0, while the opposite end of saidcoil is connected with terminal 0 the end of coil 61 with terminal 0 andthe end of coil 61 with terminal 0. ContactplatesZ Z Z are arranged toengage the sev eral terminals, while contact-plate Z is arranged toengage the terminals 0 h. The plate Z is carried upon the core 70 ofmagnet 70, which core also carries plate Z adapted to engage terminals ZZ". Said core also carries plate m, normally in contact with terminals m471?. plate land also a plate m engaging terminals m m The core 19 ofmagnet 19 carries plate Z and also plate m, engaging terminals m m andthe core 7" of magnet 1' carries plate Z and also plate m engagingterminals m and m which are connected together by resistance m Theopposite ends of winding 19 are connected with terminals m while theopposite ends of winding 7 are connected with the terminals m m and inthe normal position these coils are short-circuited.

The terminal Z is connected by conductor 16' with the brush'e of thearmature 6, while the other brush (2 is connected by conductor 17 withthe end of resistance-coil d and also with terminal m Then thecontrolling-switch is operated to close together terminals k and 7c,current flows from main 1 over conductors 12 and 13 through magnet 7r,conductor 14, resistance '73, conductor 15, through the switch toterminal 2.

Magnet 7c is thus energized and attracts core thereby moving plate Zinto engagement with the terminals h and c and moving plate Z intocontact with terminals Z Z and moving plate m out of engagement Withterminals m m The short circuit about resistance 75 is thus opened andresistance 7c is inserted in the circuit of magnet 71: to cut down thecurrent therethrough, Current from main 1 now passes over conductor 12,terminal h, plate Z and terminal a and thence through thearmature-resistance d (1 d conductor 17, and armature e to the op positemain Circuit is thus closed through all of the armature-resistances,After passing through the armature-resistance a portion of The core 0 ofmagnet 0 carries IIO the current passes through contacts m m m, thencethrough contacts m 017. m thence by conductor 18 through contacts m m mand conductor 19 through magnet 0, thence to terminal Z, contact-plate Zterminal Z and by conductor 16 to the opposite side of the circuit. Themagnet 0 is thus connected in shunt-circuit With the armature e, andwhen the counter electroinotive force of the armature is built up to aprearranged value magnet 0 is energized, thereby attracting the.

core 0 and moving plate 1 into engagement with terminals 0 c toshort-circuit resistance (1 and move plate on out of engagement withcontacts m 072 thereby including in the sh untcircuit the winding 19.The shunt-circuit around the armature now includes contacts m m m,contacts 771 m m current then passing through magnet 19 and magnet o,and thence through contacts Z Z Z and conductor 16 to the other side ofthe line. When the counter electromotive force of the armature builds upto another prearranged value, the magnet 19 is energized, attracting thecore 19 and moving plate Z into contact with terminals c c and movingplate m out of contact With terminals 772" m The second resistance (1 isthus short-circuited and removed from the armature-circuit, and theshort circuit around the coil r is opened, so that the shuntcircuitaround the armature now includes contacts m m m, magnet r, magnet p, andmagnet o, the current then passing through contacts Z Z Z and conductor16 to the opposite side of the circuit. When the counter electromotiveforce of the armature has built up to a third prearranged value, magnetr is energized, thereby attracting core 1" and moving plate Z intocontact With terminals 0 c and moving plate m" out of contact withterminals m m. The shunt around the armature now includes contact mresistance m contact m, and magnets r, p, and 0, and the placing of thethree magnets in series and the inclusion of the resistance m in circuittherewith cuts down the current to a value just sufficient to maintainthe cores in the elevated position.

Having described my invention, What I claim as new, and desire to secureby Letters Patent, is-

1. In combination an electric motor and a resistance therefor, in serieswith the armature, a plurality of electromagnets adapted to besuccessively energized to remove the re sistance from circuit step bystep, and means controlled by an electromagnet first to operateforoperatively including a succeeding electromagnet in circuit,substantially as described.

2. In combination, an electric motor and a resistance therefor, two ormore electromagnets adapted to be successively energized to remove theresistance from circuit step by step, a short circuit around one of saidelectromagnets,and means controlled by the other electromagnet foropening said short circuit to include said short-circuited electromagnetoperatively in circuit, substantially as described.

3. In combination, an electric motor and a resistance therefor,an'electromagnet adapted to be included in a parallel branch around thearmature a second electromagnet, and means operated by said firstelectromagnet for including said second electromagnet in a parallelbranch around the ar|nature,substantially as described.

4:. In combination, an electric motor and a resistance therefor, anelectromagnet adapted to be included in a parallel branch around thearmature, a second electromagnet, and means operated by said firstelectromagnet for including said second electromagnet in series withsaid first electromagnet in said parallel branch, substantially asdescribed.

5. In combination, an electric motor and a resistance therefor, anelectromagnet in a branch of definite resistance in parallel with thearmature, a second electromagnet, and means operated by the firstelectromagnet for including the second electromagnet in parallel withthe armature in a branch of greater resistance, substantially asdescribed.

6. In combination, an electric motor and a resistance therefor, aplurality of electromag= nets adapted to be connected in parallel withthe armature, and means operated by the respective electromagnets forincluding the succeeding electromagnet in a parallel path of increasedresistance, substantially as de= scribed.

7. In combination, an electric motor and a resistance therefor, aplurality of electromagnets adjusted to be energized by the flow of acurrent of definite value, and means operated by the electromagnets forincluding the same in parallel paths of successivelyincreasedresistance,substantially as described.

In Witness whereof I have hereunto subscribed my name in the presence oftwo witnesses.

HENRY- H. CUTLER. Witnesses:

W. CLYDE J onus, PERCY O. GILL.

